1. Field of the Invention
This invention relates to a bicycle trailer for towing by a bicycle, more particularly to a bicycle trailer with a carrier frame and two foldable roof supporting rods which can be easily turned upward to an upright position and downward to a storage position.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional bicycle trailer 1 is shown to include a looped carrier frame 11, a pair of support rods 12, a top bracing rod 121 for bridging the support rods 12, a connecting device 14 for connecting the carrier frame 11 to a bicycle (not shown) two wheels 15 mounted on two side portions 112 of the carrier frame 11, and a roof 17 mounted to the support rods 12 and the carrier frame 11.
Two pairs of vertical stubs 113 extend upward from the carrier frame 11. Four quick-releasing locking units 13 are connected to ends of the support rods 12 and the stubs 113. With reference to FIGS. 2 and 3, each locking unit 13 includes a lower half 133 which has a lower tubular section 135 sleeved securely on the stub 113 and an upper annular ring 130 with teeth 136, an upper half 134 which has an upper annular ring 138 provided with teeth 1381 to mesh with the teeth 136 and an upper tubular section 137, a compression spring 131 interposed between the rings 130, 138, and a lock bolt 1392 extending through the rings 130, 138 to engage a nut 1391. The lock bolt 1392 is riveted eccentrically to a stop cam 132 by a rivet 1393 so as to fasten the upper half 134 to the lower half 133 by rotating the cam 132. Thus, the pivotal connection of the support rods 12 with the stubs 113 is achieved.
However, when the support rods 12 are to be turned downward to the storage position, the top brace rod 121 must be detached from the support rods 12 before the connection between the lower and upper annular rings 138, 130 can be loosened by rotating the stop cam 132, thereby resulting in inconvenience during assembly and disassembly of the trailer 1. In addition, the construction of the quick-releasing locking units 13 complicates the manufacture of the same.